1. Tropical storms Classification Development Trajectories Forecasting Hazards Future prospects

2. Tropical disturbances, etc.

3. Saffir-Simpson scale

4. Spawning areas for tropical storms (SST >27°C)

5. Tropical storm genesis: convergence behind an easterly wave In a typical hurricane season some 60 easterly waves develop in the North Atlantic. Only about 1 wave in 5 becomes a tropical depression. Strong upper level troughs and westerly winds commonly suppress hurricane formation

6. Mature hurricane Development fostered by release of heat from condensed water in bands of clouds around the tropical storm centre more rapid convergence and updrafts. This +ve feedback leads to intensification and hurricane formation.

7. Structure of Hurricane Gilbert (Doppler radar cross-section )

8. The Atlantic hurricane season (Dr. William Gray @ Colorado State U.) Strong El Niño suppresses hurricanes (but 1998?) Wet springs inhibit hurricanes Strong Azores High inhibits hurricanes Strong stratospheric easterlies suppress hurricanes Low SST’s inhibits hurricanes

9. Atlantic hurricanes (1995 season)

10. Tracks of typhoons affecting the China Sea region

11. Tracks of cyclones in the northern Indian Ocean

12. Effects of travelling high and low pressure systems on hurricane paths

13. Hurricane Andrew (1992)

14. Hurricanes - examples of unpredictability

17. Forecasting NHC (Miami) uses nine tracking and intensity models to forecast hurricane movement. Seven models based on global climate forecasts; two (NHC90/91 and CLIPER) based on statistical analyses of past hurricane trajectories. Forecasts are for 12h, 24h, 36h, 48h and 72h ahead and are updated at 4h intervals. Some models are used for ‘early’ stages; others for ‘late’ (i.e. close to landfall). Average errors vary from ocean to ocean, depending on typical recurvature (Atlantic errors are large)

18. Mean error (nm) for Atlantic hurricanes (1996-97 seasons) Forecast model

19. The geography of forecasting error 72 h 48 h 24 h

20. Estimated annual deaths from hurricanes in the USA

21. Damages from hurricanes in the USA ($ billions)

22. Hurricane hazards Storm surge (5-6m common) High winds (see Saffir-Simpson) Intense rainfall Increasing population at risk (80% of residents of Florida =8M people live within 8 km of coast; 3M within storm surge zone) X New Orleans (-2m elev.) ~72h to evacuate 1.6M residents. Old and poor (~100 000) who rely on public transport present a major problem. Solution: move them to high floors of skyscrapers?

23. El Niño events and tropical storm activity (e.g. 1998 El Niño) PACIFIC OCEAN - 14 tropical storms in E. Pacific ; 9 developed into hurricanes. ATLANTIC OCEAN - 14 tropical storms; 10 developed into hurricanes. H. George: most powerful storm in ~200 yrs; hit Puerto Rico, Virgin Is., Domincan Rep., Florida and US Gulf coast - 300 deaths, $5G in damage. H. Mitch: most destructive storm in ~200 yrs; hit Nicaragua - Guatemala - >13 000 dead or missing, $5G in damage.

24. Global warming and tropical storm activity Emanual (MIT) forecasts: 1. that the hurricane season will be extended by 2 months or more in the North Atlantic and Caribbean. 2. that hurricane intensity will increase by more than 50% - attaining maximum wind speeds of >300 km/h (cf. >200 km/h at present).

25. HURRICANE SEASON 2001 12 - 7 - 3 12 NAMED STORMS 7 HURRICANES 3 MAJOR STORMS

26. 1995-2000 MOST ACTIVE 6 YEARS ON RECORD 79 NAMED STORMS 49 HURRICANES 24 MAJOR STORMS

30. PB4Y-2 PRIVATEER(Hurricane Hunter) Lost, Hurricane JANET - 1955

31. COSMOSPHERE-HURRICANE SUN PROVIDES HEAT

35. ATMOSPHERE-HURRICANE

36. SST 26.5C OR MORE DEEP TO A LEAST 46 METERS TEMPERATURE

38. INFLOW-OUTFLOW WARM/MOIST CORIOLIS SHEAR

39. 155 MPH = 100 lbs per SQUARE FOOT. CUBIC YARD SALT WATER = 3/4 TON. SURGE WINDS

40. HYDROSPHERE-HURRICANE OCEAN PROVIDES MOISTURE

43. BIOSPHERE-HURRICANE HABITAT DAMAGE

46. Board “Growing” in a Tree Hurricane Andrew, 1992

47. ANTHROPOSPHERE/GEOSPHERE- HURRICANE “A-SPHERE” DEATH & DISTRUCTION

48. 1935 FLORIDA KEYS

49. FLORIDA KEYS 1935

50. CAMILLE 1969

51. RICHELIEU APTS. PASS CHRISTIAN HURRICANE CAMILLE

52. AFTER CAMILLE HURRICANE CAMILLE

53. American Legion Post, Bay St. Louis CAMILLE

54. Hurricane Andrew, 1992

56. ERIN 1995

57. OCEANOGRAPHY 101 by ERIN

60. FLOYD ANDREW 19991992

61. WC-130 USAF(RES) HURRICANE HUNTER

62. AIRCRAFT RADAR

67. THE BIG ONE IS STILL OUT THERE